long story short. my 4.2 is toast. I was just curious if i find a 2.7 biturbo motor bolts up without major problems? will the ecu run the rest of my fun audi stuff?

 

Unfortunately, I think it is one of those things that is more trouble than it is worth. It is doable but not without some major work. The transmissions are also different so that would probably cause issues as well

-not an expert

 

It would be cheaper and faster to replace the car than make that swap.
Every thing is different, it's too much typing to list all the mismatches.